{"id":39805,"date":"2019-10-04T06:30:19","date_gmt":"2019-10-04T10:30:19","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=39805"},"modified":"2021-12-12T22:26:56","modified_gmt":"2021-12-13T02:26:56","slug":"final-review-of-the-commradio-ctx-10-qrp-general-coverage-transceiver","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2019\/10\/final-review-of-the-commradio-ctx-10-qrp-general-coverage-transceiver\/","title":{"rendered":"Final review of the CommRadio CTX-10 QRP general coverage transceiver"},"content":{"rendered":"

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Earlier this year I published what I called an “initial” review<\/a> of the CommRadio CTX-10 QRP transceiver, promising an eventual final review. The reason for this is that I sensed there were important CTX-10 updates on the horizon, and I wanted to re-evaluate the rig once the upgrades had been implemented through firmware.<\/p>\n

This final review builds upon the initial review<\/a>\u2013\u2013think of it as the\u00a0 second installment, or “Part 2″\u2013\u2013so if you’re considering the purchase of a CTX-10 and haven’t read the previous post about it, please do read the initial review<\/a> first<\/strong>.<\/p>\n

Upgrades<\/h1>\n

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As anticipated, via simple at-home firmware updates, since my initial review the CTX-10 has now been upgraded and tweaked a number of times<\/strong>. [Click here to view all of the documented firmware updates and notes at CommRadio.<\/a>]<\/p>\n

I’ve been very pleased with the attention CommRadio has paid to their customer feedback on some of the most important requests.<\/p>\n

Instead of reiterating what I wrote in the initial review, I’ll jump straight into the upgrades.<\/p>\n

Operating split<\/h2>\n

At time of posting my initial review, the CTX-10 didn\u2019t have A\/B VFOs. This was my primary gripe about the CTX-10, because without A\/B VFOs, there was no way to operate split, which meant that you could not work DX stations that use split to manage large pileups. This is actually a really important feature for a QRP radio because during split operation, a pileup is pulled apart across a few kHz of bandwidth, thus giving a 10-watt signal a better chance of being heard through a collection of legal-limit signals.<\/span><\/p>\n

On June 10, 2019, CommRadio released a firmware package that added A\/B VFOs and the ability to operate split to the CTX-10.<\/strong><\/p>\n

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Even though there are only a limited number of buttons on the front panel, it’s incredibly simple to enter into split mode:<\/p>\n

    \n
  1. Chose the frequency and mode;<\/li>\n
  2. Hold the STEP button for one second or more, then release. Y<\/span>ou’ll then see a split display indicating the TX and RX frequencies. <\/span><\/li>\n
  3. Use the left arrow key [<] to toggle between them.<\/span><\/li>\n<\/ol>\n

    I do like the clear TX and RX lines, which leave no doubt in the user’s mind what the frequency used for transmitting and receiving is. On some radios, this can be a bit confusing.<\/p>\n

    Split operation is simple and effective, thus I consider this issue fully resolved.<\/strong><\/p>\n

    ATU flexibility<\/h2>\n

    In my initial review, I noted that the CTX-10 ATU needed near-resonant antennas for the ATU to make a strong 1:1 match. Indeed, a number of times I actually used a near-resonant antenna in the field\u2013\u2013the EFT Trail-Friendly, for example\u2013\u2013and the ATU couldn’t get below a 3:1 match. For what it’s worth, CommRadio states that the CTX-10 can easily handle 3:1.<\/p>\n

    \"\"<\/a>

    Making a Parks On The Air activation at Tar Hollow in Ohio.<\/p><\/div>\n

    CommRadio has made modifications to the ATU function,<\/strong> improving the performance of the antenna-tuner algorithm, which had a significant impact on 80 and 60 meters. I’ve also had better luck with a number of field antennas I’ve tried on 40 and 20 meters. Is it as good as the Elecraft KX-series ATUs? No.<\/p>\n

    Having a built-in ATU on the CTX-10<\/strong> is certainly a valuable feature in the field. When I need to match a challenging antenna with the CTX-10, I bring my Emtech ZM-2<\/a> manual tuner along for the ride.<\/p>\n

    SSB operation?<\/h2>\n

    There still is no way to adjust the microphone gain control<\/b> nor microphone compression<\/strong> on the CTX-10. Much like a military or commercial radio, the CTX-10 is optimized for just one style of mic: in its case, the modular MFJ-290MY<\/strong> or Yaesu MH-31A8J<\/strong> handheld mic.<\/p>\n

    \"\"<\/a><\/p>\n

    The CTX-10 microphone input has a limiting pre-amplifier with built-in compressor and ambient noise gate–in short, the CTX-10 handles all microphone settings automatically.<\/p>\n

    Through firmware updates, a number of positive adjustments have been made to the microphone settings:<\/p>\n